This descriptive cross-sectional study will examine how patients weigh factors that affect decision making about participation in Phase-I clinical cancer trials. It will use interviews with patients and their doctor and/or nurse to collect data about general health concerns, assessment of risks vs. benefits, and the patient-physician relationship. The purposes of this study are to develop questionnaires to define the factors patients and their doctors use to make decisions; to test these tools with many cancer patients; to determine if the results of these interviews can be useful for improving patient-physician communication about phase-I studies; and to improve how Phase-I studies are designed and conducted. The study will enroll about 500 patients nationally over 18 months. Baseline and 3-month follow-up patient interviews, and surveys of research nurses and physicians for each patient, will be conducted.